Year	Number of
1990	248.71
1991	252.9
1992	256.99
1993	260.51
1994	264.06
1995	267.82
1996	272.42
1997	277.36
1998	283.67
1999	291.03
2000	299.72
2001	306.95
2002	315.89
2003	327.78
2004	340.7
2005	354.54
2006	367.03
2007	380.28
2008	394.99
2009	411.74
2010	431.14
2011	448.62
2012	468.54
2013	488.65
2014	511.2
2015	536.28
2016	564.11